We find that recombination of Plp1 in excitatory projection neurons does not cause neuropathology, whereas oligodendroglial targeting of Plp1 is sufficient to cause the entire neurodegenerative spectrum of SPG2 including axonopathy and secondary neuroinflammation.
A boy with spastic paraplegia type 2 (SPG2) due to a novel splice site mutation of PLP1 presented with progressive spasticity of lower limbs, which was first observed during late infancy, when he gained the ability to walk with support.
Pelizaeus-Merzbacher disease (PMD), a hypomyelinating leukodystrophy, and the related but less severe allelic spastic paraplegia 2 (SPG2) are caused by mutations in the proteolipid protein 1 (PLP1) gene.
Proteolipid protein 1 (PLP1) gene-related disorders due to mutations in the PLP1 include a wide spectrum of X-linked disorders ranging from severe connatal Pelizaeus-Merzbacher disease (PMD) to spastic paraplegia 2 (SPG2).
Various types of mutations of the X-linked proteolipid protein 1 gene (PLP1) that include copy number changes, point mutations, and insertions or deletions of a few bases lead to a clinical spectrum from the most severe connatal PMD, to the least severe spastic paraplegia 2 (SPG2).
We report an autopsy case of rare adult-onset spastic paraplegia type 2 (SPG2) with a novel missense mutation in exon 7 of the proteolipid protein 1 gene (PLP1).
PLP1 gene mutations are associated with a large spectrum of X-linked dysmyelinating disorders ranging from hypomyelinating leukodystrophy, Pelizaeus-Merzbacher disease (PMD), to spastic paraplegia (SPG2) according to the nature of the mutation.
The disease spectrum for PMD and SPG2 is extraordinarily broad and can be best understood by accounting not only for the wide range of mutations that can occur but also for the effects of PLP1 mutations on both cell autonomous and non-cell autonomous processes in myelinating cells.
In addition, spastic paraplegia 2 (SPG2) is allelic to PMD and typically caused by missense mutations in the second extracellular domain of PLP1 or in the PLP1-specific region that is spliced out during formation of the DM20 isoform.
Here we review the dosage effects and mutations of the proteolipid protein (PLP) gene that causes Pelizaeus-Merzbacher disease (PMD) and spastic paraplegia Type 2 (SPG2) disorders of CNS myelination.
The complicated form is heterogeneous, caused by mutations of the L1CAM gene at Xq28 (SPG1) or the PLP gene at Xq22 (SPG2) that is allelic to Pelizaeus-Merzbacher disease (PMD).
We report a dinucleotide polymorphism in the first intron of the proteolipid protein (PLP) gene with a heterozygosity frequency of 0.69 useful for molecular analysis of families with X-linked neurologic disorders characterized by dysmyelination of the central nervous system, Pelizaeus-Merzbacher Disease (PMD) and X-linked Spastic Paraplegia (SPG2).